package cn.edu.just.firstjavaapp.l5;

public class Rectangle {
    final  int xxx = 100;
    int x;   //instance variable
    static int count;// class variable

    public int add(int a,int b){  //instance method
        //xxx = 200;
        return a+b;
    }

    public static void copy(Rectangle r){  //class method


    }

    public static void main(String[] args) {
        Rectangle.copy(null);
        Rectangle.count=1;
        //Rectangle.add(1,3);
        //Rectangle.x = 10;

        Rectangle r = new Rectangle();
        r.x=10;
        r.add(4,5);
        r.count=10;
        r.copy(null);
    }
}
